Cutlery polishing machine

ABSTRACT

A machine for polishing workpieces such as cutlery and other small articles, where the polishing roller, or rollers, are enclosed inside a container holding the polishing mixture in the form of a low-viscosity liquid, and the workpieces held by a reciprocating work frame are introduced from above through a restricted opening to the work area on the roller periphery. The polishing liquid is kept in constant agitation and continuously fed to the rollers either by the rollers dipping into the liquid, or by a circulatory system with a squeeze pump, whereby the polishing liquid acts as an effective coolant.

United States Patent Germany by Dorothea Hauschild, heiress Filed: May 19, 1971 Appl. No; 144,788

Foreign Application Priority Data May 19, 1970 Germany P 20 24 379.2

References Cited UNITED STATES PATENTS 8/1918 Mellien ..15/39 6/1937 Turco 15/39 Hauschild et a1. 1 1 Oct. 2, 1973 CUTLERY POLISHING MACHINE 2,202,516 5 1940 Calleo 15 39 ux [76] Inventors: Willi Hauschild, Schillerstrasse 22,

Feldkirchen, Germany; 3:O81:47l 3/1963 Newell llauschild, deceased, late of 3 4 4 030 911969 Ceylon,

Marienstrasse ll, Neuwied, 3,643,277 2/1972 Durst 15/77 Primary Examiner-Edward L. Roberts Att0rneyArthur Schwartz et al.

[57] ABSTRACT A machine for polishing workpieces such as cutlery and other small articles, where the polishing roller, or rollers, are enclosed inside a container holding the polishing mixture in the form of a low-viscosity liquid, and the workpieces held by a reciprocating work frame are introduced from above through a restricted opening to the work area on the roller periphery. The polishing liquid is kept in constant agitation and continuously fed to the rollers either by the rollers dipping into the liquid, or by a circulatory system with a squeeze pump, whereby the polishing liquid acts as an effective coolant.

PATENTEDHETDZIW 3.761.984

SHEETIUFZ Fig.1

INVIIN'I'ORI HANS HAUSCHILD, Deceased WILLI HA USCHILD PATENTEDUBT' 21915 3 .761 ,984

SHEET 2 OF 2 INVllN'I'ORI HANS HAUSCHILD, Deceased WILLI HAUSCHILD CUTLERY POLISHING MACHINE BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to polishing machines, and in particular to machines for polishing cutlery and other small metal articles using a polishing roller and a continuous supply of polishing mixture in liquid form.

2. Description of the Prior Art Various automatic cutlery polishing machines have been suggested in the past, one such machine being described in the German Auslegeschrift No. 1,237,924. In this case, the cutlery pieces to be polished are arranged in succession on a conveyor consisting of two endless chains in a parallel arrangement. The conveyor moves through a laterally open rotating drum in the axial direction. Above the conveyor is provided an elongated polishing roller, also extending axially across the drum but at an angle to the conveyor. The rotating drum which holds a certain amount of polishing mixture carries the latter above the roller, where fixed wipers guide the mixture onto the polishing roller.

In order to work all surface portions of the cutlery pieces, and especially the bottom of their concave surface portions, the size of the roller brush must be kept small in diameter. This made it necessary to arrange the roller brush at an angle to the conveyor to assure that the entire length of the cutlery pieces passing underneath the roller is worked. This arrangement has the shortcoming that some of the fluid polishing mixture is ejected from the ends of the roller brush through the open sides of the drum, while further loss of polishing mixture occurs through evaporization and atomization of the mixture and through escape of these vapors from the drum. One way to counteract these problems is to radically reduce the speed of the roller brush, with the result, however, that the operating capacity is reduced correspondingly. Moreover, the surface quality attainable under such circumstances is lowered. Indeed, the general procedure as suggested in this prior art solution is inadequate for cases where a high-quality, perfectly even surface treatment is necessary.

A further disadvantage of the above device is the space required for the rotating drum, adding to the problems of structural support and drive, in view of current industrial safety standards. The amount of polishing fluid usable at any one time is limited, and the fluid itself must be sufficiently viscous to adhere to the walls of the drum so as to be carried upward.

In principle, it was found to be preferable to use liquid polishing mixtures, because they can be applied easily and in any quantity and because they can be produced from inexpensive raw materials, especially when using water as the carrier liquid. Liquids have the additional advantage of producing a convenient cooling effect on the polishing rollers and workpieces where considerable heat is normally developed. The use of liquid mixtures thus greatly reduces the previously experienced deterioration of the surrounding plant atmosphere through smoke and vapors originating from the burn-off on the polishing rollers and the vaporization of the polishing fluid.

SUMMARY OF THE INVENTION In view of the earlier-mentioned problems, it is an objective of the present invention to provide an improvement over the prior art devices by fully utilizing the characteristics and advantages of liquid polishing mixtures. The invention suggests in particular, a way in which the polishing liquid can be used in a low-viscosity state and in sufficient quantity to provide for effective cooling of the high-speed polishing rollers as well as of the workpieces. With a device as suggested by the invention, the polishing liquid is no longer subject to loss from ejection and vaporization, the burn-off and chipping of the bristles of the polishing rollers are no longer a problem, and the polishing liquid maintains its consistency and composition over a longer period. The latter, after exhaustion, can be removed from the device and replaced in a very simple procedure. In addition to the operational advantages, the device of the invention is of a structure which is economic to produce, simple in maintenance, and safe as an industrial installation.

The invention proposes to attain the above objective by suggesting a polishing machine where the polishing roller is arranged inside a substantially closed container holding the polishing liquid, while a plurality of cutlery pieces or similar articles to be polished are introduced into the container from above in the direction of a tangent to the polishing roller. The cutlery pieces are attached, in a known way, to a common reciprocating work frame. The polishing mixture is fed to the polishing roller in one of two ways: in one version the lower portion of the polishing roller dips into a bath of polishing liquid; in the other version the liquid is fed to the upper portion of the polishing roller by a pump and conduit system. In both cases, the machine user himself can easily and inexpensively produce a suitable polishing mixture, and the mixture, where desired, is easy to regenerate.

From German Pat. No. 304,635, it is known to suspend grinding abrasives in a liquid solution and to maintain the mixture in constant circulation by means of a pump. In contrast thereto, it was believed as indicated in the German Pat. No. 947,682 that polishing abrasives in liquid solution, because of their structure, are neither conveyable by pumping, nor capable of continuous circulation through pipes or hoses. It was discovered, however, that polishing mixtures in the form of a comparatively easy-flowing, low-viscosity liquid, such as are to be used in the device invented, can be circulated by means of certain pumps, for example, by means of squeeze pumps used to convey mixed concrete. Tests have shown that in a circulatory system.

where the cross-sectional discontinuites are carefully minimized, a sufficiently high and even flow speed of the polishing liquid can be maintained to prevent clogging and the formation of deposits of polishing abrasive in the conduits.

BRIEF DESCRIPTION OF THE DRAWINGS Further special features and advantages of the invention will become apparent from the description following below, when taken together with the accompanying drawings which illustrate, by way of examples, two embodiments of the invention, represented in the several figures as follows:

FIG. 1 shows, in an elevational cross-section, a first embodiment of the invention where the two parallel polishing rollers dip into a bath of polishing liquid;

FIG. 2 shows, in a comparable elevational crosssection, a second embodiment of the invention, where the polishing mixture is fed to the polishing rollers by a circulatory system; and

FIG. 3 shows in enlarged detail a modification of the embodiment of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT The two embodiments shown in FIGS. 1 and 2 have in common two oppositely rotating, parallel polishing rollers 1 and 2, arranged horizontally inside substantially closed containers 3 which hold a polishing liquid 9. In each case, the container cover 4 includes a narrow longitudinal opening 5 corresponding to the length of the rollers, to allow the introduction of a plurality of cutlery pieces 6 between the rollers 1 and 2. The cutlery pieces 6 are held in a work frame 23 by known means. The work frame 23 is driven to give to the cutlery pieces a reciprocating motion in the direction of arrow 7. Each polishing roller engages one side and/or flank of the cutlery pieces, while the latter reciprocate in their axial direction over the desired length to be polished.

The arrangement with two polishing rollers facing one another has the double advantage that a large part of the polishing mixture ejected from one roller is caught by the opposite roller, and that the polishing pressures necessary between the workpieces 6 and the rollers 1 and 2 are equalized. This permits the work frame 23 to be built lighter in weight and less expensive. It also eliminates the need for any additional support on the lower ends of the workpieces 6.

As can be seen from the drawings, the direction of rotation of the polishing rollers is clockwise for roller 1 and counter-clockwise for roller 2, so that no polishing liquid is ejected from the opening 5. If necessary, the cover 4 may also include oppositely arranged longitudinal sealing lips 8 which may be in the form of flat brushes.

In the embodiment of FIG. 1 the polishing liquid is fed to the polishing rollers 1 and 2 by the fact that the level of the polishing liquid 9 inside the container 3 is such that the rollers dip into the polishing liquid with the lower portion of their periphery. In this case, it may be advisable to provide a wiper 10 for each roller, in order to remove any excess of polishing liquid from the rollers and to reduce splashing. The wipers 10 need not contact the polishing rollers.

The embodiment of FIG. 1 further includes an agitator inside the container, the agitator including, for example, a rotating agitator blade 11 which is driven by a gear motor 12. Thus, the polishing liquid in the container 3 is maintained in continuous agitation thereby preventing the polishing abrasive from forming deposits on the container bottom, while simultaneously improving the cooling process through better heat conduction to the container walls. In certain cases, however, the agitation provided by the rollers dipping into the liquid may be sufficient. It is also suggested that any dead corners, sharp angles and recesses in the container contour be avoided to minimize the formation of abrasive deposits.

In the embodiment of FIG. 2 the polishing rollers l and 2 rotate freely without dipping into the liquid 9 inside container 3. Here, the liquid is drawn from the container 3 at its lowest point and is forcibly circulated by means of a pump 13 through the horizontal pipe 14 and the vertical pipe 15 to a branch 16 above the container. From the branch 16, the polishing liquid reaches two valves 17 and 18, operable preferably independently of each other, and, via the feed pipes 19 and 20, it is discharged through the nozzles 21 and 22. These nozzles are so arranged that the polishing liquid flows onto the polishing rollers 1 and 2 immediately above the point of contact with the workpieces 6 and in a continuous stream as large as the working length of the polishing rollers.

The circulation pump 13, though shown schematically as a centrifugal pump, is preferably of the squeeze-pump-type, using a flexible hose and squeeze rollers, similar to devices employed in the pumping of mixed concrete. This type of pump promises a comparably great longevity in spite of the abrasiveness of the polishing liquid.

The generously flowing, low-viscosity polishing liquid guarantees excellent cooling of the work area. Nevertheless, no ejection of polishing liquid to the outside takes place, thanks to the design configuration suggested by the invention.

As an alternate mode of forcible ciruclatory feeding of polishing liquid to the rollers l and 2, it is also possible to pump the liquid 9 through axial bores 24 in the roller shafts from where the liquid is fed by centrifugal force through rows of radial holes 25 to the periphery of the roller brushes. This alternative is illustrated in FIG. 3. It should be obvious from the above that, in this case, the opening 5 in the cover 4 of the container can be as narrow as in FIG. 1, because of the absence of the nozzles 21 and 22.

The container 3 of the embodiment of FIG. 2 is shown to have tapered walls in the shape of a funnel, the purpose of this shape being the need for continuous circulation of the liquid at all places inside the container 3. Under certain circumstances, it may be advisable to add an agitator even in the embodiment of FIG. 2.

It is also possible to incorporate a separator in the circulatory system shown in FIG. 2. Such a separator would be used to remove from the used polishing mixture that portion of the polishing base material whose particle size has become too small. To the separator may be added a device whereby corresponding amounts of new polishing base material may be added automatically to the circulatory system.

We claim:

1. A machine for polishing workpieces such as cutlery and other metal articles, comprising in combination:

a container which is substantially closed on all sides;

at least one polishing roller arranged for rotation inside the container, including a drive means therefor;

a restricted opening in the container for the introduction of workpieces into tangential contact with the periphery of the polishing roller in a work area;

an oscillating frame arranged outside the container in the vicinity of its restricted opening, the frame holding the workpieces so that the latter reach into the work area and oscillate relative to the polishing roller;

an abrasive polishing mixture inside the container,

the polishing mixture including a low-viscosity carrier liquid and a particulate abrasive material dispersed in it through agitation; and

means for agitating the polishing mixture to maintain its abrasive material in dispersion and means for continuously feeding polishing mixture to the work area, whereby the carrier liquid acts as a coolant for the polishing roller and the workpieces.

2. The machine as defined in claim ll, wherein:

two oppositely rotating horizontal polishing rollers are arranged in parallel with one another in the upper portion of the container so that the two rollers face one another in the work area, ,the restricted opening being in the top of the container.

3. The machine as defined in claim 2, wherein the oscillating frame executes a reciprocating motion to advance and retract the workpieces in the work area in a substantially tangential direction on both polishing rollers.

4. The machine as defined in claim 1, further comprising:

a flexible seal extending across the restricted open' ing, the seal including oppositely oriented flexible brush members.

5. The machine as defined in claim ll, wherein the feeding means for the polishing mixture is provided by the rotation of the polishing roller, the latter being so positioned relative to the polishing mixture that it entraines a portion of the mixture during its rotation.

6. The machine as defined in claim ll, wherein the agitating means and the feeding means for the polishing mixture are combined in a circulatory system comprising pumping means and conduit means for the forcible feeding of the polishing mixture to the work area.

'7. The machine as defined in claim 6, wherein the conduit means are of negligeable cross-sectional discontinuity to maintain a substantially continuous flow speed therein, thereby preventing clogging and deposit formation in the circulatory system.

8. The machine as defined in claim 6, wherein at least its bottom container includes tapered walls giving it a funnel-shaped contour in the portion, the outlet to the circulatory system being located at the bottom of the funnel.

9. The machine as defined in claim 6, wherein the conduit means of the circulatory system include an axial conduit in the center of the polishing roller and radial outlets leading to the roller periphery.

lit). The machine as defined in claim 6, wherein the conduit means include a downwardly oriented nozzle, the polishing liquid being fed through the nozzle to the work area.

ill. The machine as defined in claim 6, wherein the pumping means includes a squeeze pump and a drive therefor, the squeeze pump comprising a flexible hose and cooperating squeeze rollers.

12. The machine as defined in claim 1, wherein the agitating means for the polishing mixture includes an agitator and a drive therefor, the agitator being arranged in the bottom portion of the container.

13. The machine as defined in claim 1, further comprising:

means for separating from the polishing mixture those used abrasive particles which have a particle size below a predetermined value; and

means for adding to the polishing mixture fresh abrasive particles of larger size. 

1. A machine for polishing workpieces such as cutlery and other metal articles, comprising in combination: a container which is substantially closed on all sides; at least one polishing roller arranged for rotation inside the container, including a drive means therefor; a restricted opening in the container for the introduction of workpieces into tangential contact with the periphery of the polishing roller in a work area; an oscillating frame arranged outside the container in the vicinity of its restricted opening, the frame holding the workpieces so that the latter reach into the work area and oscillate relative to the polishing roller; an abrasive polishing mixture inside the container, the polishing mixture including a low-viscosity carrier liquid and a particulate abrasive material dispersed in it through agitation; and means for agitating the polishing mixture to maintain its abrasive material in dispersion and means for continuously feeding polishing mixture to the work area, whereby the carrier liquid acts as a coolant for the polishing roller and the workpieces.
 2. The machine as defined in claim 1, wherein: two oppositely rotating horizontal polishing rollers are arranged in parallel with one another in the upper portion of the container so that the two rollers face one another in the work area, the restricted opening being in the top of the container.
 3. The machine as defined in claim 2, wherein the oscillating frame executes a reciprocating motion to advance and retract the workpieces in the work area in a substantially tangential direction on both polishing rollers.
 4. The machine as defined in claim 1, further comprising: a flexible seal extending across the restricted opening, the seal including oppositely oriented flexible brush members.
 5. The machine as defined in claim 1, wherein the feeding means for the polishing mixture is provided by the rotation of the polishing roller, the latter being so positioned relative to the polishing mixture that it entraines a portion of the mixture during its rotation.
 6. The machine as defined in claim 1, wherein the agitating means and the feeding means for the poliShing mixture are combined in a circulatory system comprising pumping means and conduit means for the forcible feeding of the polishing mixture to the work area.
 7. The machine as defined in claim 6, wherein the conduit means are of negligeable cross-sectional discontinuity to maintain a substantially continuous flow speed therein, thereby preventing clogging and deposit formation in the circulatory system.
 8. The machine as defined in claim 6, wherein at least its bottom container includes tapered walls giving it a funnel-shaped contour in the portion, the outlet to the circulatory system being located at the bottom of the funnel.
 9. The machine as defined in claim 6, wherein the conduit means of the circulatory system include an axial conduit in the center of the polishing roller and radial outlets leading to the roller periphery.
 10. The machine as defined in claim 6, wherein the conduit means include a downwardly oriented nozzle, the polishing liquid being fed through the nozzle to the work area.
 11. The machine as defined in claim 6, wherein the pumping means includes a squeeze pump and a drive therefor, the squeeze pump comprising a flexible hose and cooperating squeeze rollers.
 12. The machine as defined in claim 1, wherein the agitating means for the polishing mixture includes an agitator and a drive therefor, the agitator being arranged in the bottom portion of the container.
 13. The machine as defined in claim 1, further comprising: means for separating from the polishing mixture those used abrasive particles which have a particle size below a predetermined value; and means for adding to the polishing mixture fresh abrasive particles of larger size. 